Tobacco curer

Abstract

A method and apparatus for curing tobacco is provided wherein each leaf is conveyed through a dual chamber curer. The stem of the tobacco leaf is disposed within the upper chamber while the leaf is disposed within the lower chamber. A pre-determined temperature difference is maintained between upper and lower chambers so that the stem and leaf are cured in approximately the same time period thereby preventing overcuring of the leaf.

What is claimed is: 
     
       1. An apparatus for curing tobacco comprising: (a) a dual chamber duct system for isolating the leaf and stem of the tobacco including an elongated stem chamber for containing the stem of the tobacco, an elongated leaf chamber adjacent to but separated from the stem chamber for containing the leaf of the tobacco, and an elongated slot-like opening communicating between said stem chamber and said leaf chamber through which the stem of the tobacco extends;   (b) means for conveying said tobacco lengthwise through said duct system, with the leaf of the tobacco taking up a substantial portion of the cross-sectional area of said leaf chamber and the stem of the tobacco projecting through said slot-like opening into said stem chamber; and   (c) an air circulating means for heating and circulating air through said stem chamber and said leaf chamber while said tobacco is conveyed through said duct system said air circulating means including means for independently controlling the temperature of the air within the leaf and stem chambers respectively.   
     
     
       2. The apparatus of claim 1 wherein said conveyor means includes a continuous, chain conveyor which extends through said duct system and means for supporting said tobacco from said chain conveyor. 
     
     
       3. The apparatus of claim 2 wherein said means for supporting said tobacco includes a plurality of clumps secured to said chain conveyor in spaced relation for engaging the stems of said tobacco. 
     
     
       4. The apparatus of claim 1 wherein said duct system is a continuous, closed loop duct system. 
     
     
       5. The apparatus of claim 4 wherein said duct system is in the form of a double helical. 
     
     
       6. The apparatus of claim 1 wherein said air circulating means includes means for varying the temperature of the heated air circulated through said stem chamber and said leaf chamber so as to establish distinct longitudinally spaced temperature zones through which said tobacco is sequentially conveyed. 
     
     
       7. The apparatus of claim 6 wherein said temperature zones gradually increase in temperature from the beginning to the end of said duct system so as to effect first the yellowing of said tobacco and then the drying of the leaf and stem. 
     
     
       8. A method for curing tobacco in a curer including an elongated stem chamber adjacent to but separated from said leaf chamber, and a slot-like opening communicating between the leaf chamber and stem chamber, said method comprising: (a) isolating the leaf and stem of the tobacco by placing tobacco within said curer so that the leaf of the tobacco is disposed in said leaf chamber and the stem of the tobacco projects through said slot-like opening into said stem chamber; and   (b) circulating heated air of different temperature through said leaf chamber and stem chamber respectively to effect the curing of the tobacco.   
     
     
       9. The method according to claim 8 further comprising the step of conveying said tobacco lengthwise through said curer while simultaneously circulating heated air through said leaf chamber and stem chamber. 
     
     
       10. The method according to claim 9 further comprising the step of varying the temperature of the heated air circulated within the stem and leaf chamber to establish distinct temperature zones distributed through which the tobacco is sequentially conveyed.